<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
    <title>Document</title>
    <style>
        .one {
            width: 100px;
            height: 100px;
            background-color: yellow;
        }

        .two {
            width: 200px;
            height: 200px;
            background-color: hotpink;
        }

        .three {
            width: 250px;
            height: 250px;
            background-color: red;
        }
        .active{
            color: red;
        }
    </style>
</head>

<body>
    <div id="app">
        <!-- 
            class强制绑定写法允许是一个对象写法,对象的key就是类型,如果这个key对应的value是truthy的值,则这个类开启
        -->
        <div :class="className"></div>

        <!-- 
            练习：判断是否拥有active
         -->
        <div :class="isActive?'active':''">test active</div>
        <div :class="{active:isActive}">test avtive</div>
    </div>
    <script>
        const vm = new Vue({
            el: "#app",
            data() {
                return {
                    className: {
                        one: false,
                        two: false,
                        three: true,
                    },
                    isActive:false,
                }
            }
        })
    </script>
</body>

</html>